In the Garden:New England
April, 2010
Regional Report

We Get By with a Little Help From Our Friends

We can all use a little help in the garden. And there is an army of tiny helpers eager to lend a hand. They are the beneficial insects, ones that behave in ways that are helpful to the crops we grow. These "good bugs" help out in a variety of ways- by hunting and eating (or using as food for their young) insects that are harmful to our crops, by parasitizing insects we consider pests, or by pollinating the fruiting plants we grow. Healthy populations of these beneficials help us to have a thriving garden with abundant yields without resorting to chemical pesticides that can be harmful to ourselves and the environment. All the good guys ask for is some food, water and shelter. Here are some ways you can encourage beneficial insects and have a more successful, and more beautiful, garden as a result.

Minimize the use of pesticides, even organic ones
Even pesticides considered acceptable for organic gardens can harm the good guys along with the bad, so try to keep any pesticide use to a minimum. If you do use one, spray in the evening after the pollinators have stopped flying. Try to choose ones with a narrow spectrum of control, like the microbial insecticide Bt, since this only affects caterpillar pests that are feeding on the sprayed plants. It's also important to have some pests around for the beneficials to feed on. If there is nothing left to eat, the beneficials will move on to greener pastures!

Plant lots of flowers to attract beneficials
What a great excuse to fill the garden with beautiful blossoms! Flowers provide pollen and nectar for the different life stages of these insects. Think daisy and umbrella when it comes to choosing flowers. Those with umbrella-shaped clusters of small flowers, such as dill, caraway, coriander, yarrow, and Queen Anne's lace are particularly appealing. Daisy-like flowers such as golden marguerite, sunflowers and aster are attractive to many beneficials. Other good choices include tansy, butterfly weed, mint, baby-blue-eyes (Nemophilia), scabiosa, candytuft (Iberis), goldenrod, bishop's flower (Ammi majus), cosmos, coreopsis, blazing star (Liatris), rudbeckia, bee balm, nasturiums, borage, fennel and zinnias. The most important thing is to have a diversity of blossoms and plant sizes blooming throughout the growing season. A border of flowers around the vegetable garden is an excellent way to provide food and shelter for beneficials, along with flower plantings mixed into the vegetable beds themselves. Since the flowers of many herbs are excellent attractors, consider locating your herb garden in the center of your food garden. And let some of your veggies go to seed- the flowers of carrots, parsley, radishes, broccoli, and turnips are also favorites. And finally, don't forget about shrubs out in your landscape. The flowers of pussy willow, spirea, summersweet (Clethra), ninebark (Physocarpus), and serviceberry(Amelanchier) all provide pollen or nectar for beneficial insects.

Provide a source of water
A shallow pool of water with some stones or piles of gravel on which insects can perch will help beneficials quench their thirst. Some insects, especially butterflies and some pollinator bees, prefer a mud puddle. Let a hose or faucet drip just a bit to form a damp, muddy sipping spot.

Give them some shelter
If you can, let a corner of your yard go "wild". A wooded area or hedgerow 10 to 20 feet north of the garden is ideal, but even a small undisturbed area will give beneficials a place to shelter and nest. You can also make nesting blocks for pollinating bees that nest in wood, such as mason bees, by drilling at least 10 holes 5 to 6 inches deep in a block of untreated wood. Hang it with the holes horizontal under the eaves on the south or east side of a building. Sections of wood pallets laid in grass near the garden will give mantids a place to deposit their eggs cases. Place some groups of flat rocks in the garden to give ground beetles a place to shelter.

Leave a little lawn
Leave a turf pathway through the garden. Turfgrass is home to predators such as ground, rove and tiger beetles, and can serve as a spot for mantids, ladybugs and other desirable insects to lay their eggs. Care for your entire lawn organically and don't obsess over manicured turf, and you'll provide good habitat for ground-nesting bees that serve as pollinators in the garden.

Learn what the good guys look like
This is important because we gardeners have a tendency to view any bug as a "bad" bug if we don't recognize it. Most of us can probably identify a ladybug as a "good guy", but we may not realize when we find a larger, ferocious-looking, black and yellow creature that it is actually a ladybug larva, bent on gobbling up aphids. And we might not know that the forest of tiny green eggs carried atop hair-thin stalks on a leaf in the garden will hatch out into fat, bristly lacewing larvae with large, tusk-like jaws, also devourers of aphids, looking nothing like the delicate, gossamer-winged green adults. The following website has a great selection of photos and information on many beneficials: http://www.inhs.illinois.edu/chf/outreach/eduresources/good/guysframes.htm